i have 2 m216 286 motherboard one of them can see 16 mb (the 1st one) while the 2nd one sees only 4mb

i am trying to mirror the broads as i know the PCBs are the same but the 2nd board is missing components so i will install them and a jumper is missing on jp2.

components include crystal at 32 mHz, 15 ohm resistor, 1 jumper.... that is all i can see